Exit Signal only after a Buy or Sell signal

Question

I am drafting a script based on a donchian channel strategy. For buy/sell signals, I require that every time the price is higher than the upper/lower line, it generates a buy or sell signal. For exit signals, I am using ATR, however I would like the signal to appear only when a buy or sell signal is generated, and not when and only the ATR changes direction. To do this, I would need the script to understand that it should plot an exit signal, only when there was a previous buy or sell signal. I came up with the script below, but I couldn't stop it from repeating the signals. Can anyone help me? Thanks!

// This Pine Script™ code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © SMTraderTradingCrypto

//@version=5
indicator(title="Donchian Channels Strategy", shorttitle="DC", overlay=true, timeframe="", timeframe_gaps=true)

//INPUTS

length = input.int(20, title = "DC Period", minval = 1)
offset = input.int(0, title = "DC Offset")
keyvalue = input(2, title = "ATR Length")
atrperiod = input(20, title = "ATR Period")
src = input(close, title = "ATR Source")

cns_len = 2

//DC FUNCTION

lower =  ta.lowest(length)
upper =  ta.highest(length)
basis =  math.avg(upper, lower)

//ATR FUNCTION

xATR = ta.atr(atrperiod)
nLoss = keyvalue * xATR

xATRTrailingStop = 0.0
iff_1 = src > nz(xATRTrailingStop[1], 0) ? src - nLoss : src + nLoss
iff_2 = src < nz(xATRTrailingStop[1], 0) and src[1] < nz(xATRTrailingStop[1], 0) ? math.min(nz(xATRTrailingStop[1]), src + nLoss) : iff_1
xATRTrailingStop := src > nz(xATRTrailingStop[1], 0) and src[1] > nz(xATRTrailingStop[1], 0) ? math.max(nz(xATRTrailingStop[1]), src - nLoss) : iff_2

pos = 0
iff_3 = src[1] > nz(xATRTrailingStop[1], 0) and src < nz(xATRTrailingStop[1], 0) ? -1 : nz(pos[1], 0)
pos := src[1] < nz(xATRTrailingStop[1], 0) and src > nz(xATRTrailingStop[1], 0) ? 1 : iff_3

//BUY/SELL FUNCTION

cns_up = 0
cns_up := nz(cns_up[1])

cns_dwn = 0
cns_dwn := nz(cns_dwn[1])

isLong = false
isLong := nz(isLong[1])

isShort = false
isShort := nz(isShort[1])

cns_up := high >= upper ? cns_up + 1 : 0
cns_dwn := low <= lower ? cns_dwn + 1 : 0

buySignal = not isLong and (cns_up >= cns_len)
sellSignal = not isShort and (cns_dwn >= cns_len)

if (buySignal)
    isLong := true
    isShort := false

if (sellSignal)
    isLong := false
    isShort := true

//EXIT SIGNAL

var lastSignal = 0

if (buySignal)
    isLong := true
    isShort := false
    lastSignal := 1

if (sellSignal)
    isLong := false
    isShort := true
    lastSignal := -1

//EXIT SIGNAL

Atrbuy = ta.crossover(src,xATRTrailingStop) and lastSignal == -1
Atrsell = ta.crossunder(src,xATRTrailingStop) and lastSignal == 1

plotshape(Atrbuy, title="Exit Signal", text="Exit", style=shape.triangleup, location=location.belowbar, color=color.red, size=size.small, offset=-1)
plotshape(Atrsell, title="Exit Signal", text="Exit", style=shape.triangledown, location=location.abovebar, color=color.green, size=size.small, offset=-1)

//COLORS

green = #00FF0A
red = #FF1100

xcolor = pos == -1 ? red : pos == 1 ? green : na

//PLOTS

u = plot(upper, "Upper", color = red, linewidth = 3, offset = offset)
l = plot(lower, "Lower", color = green, linewidth = 3, offset = offset)

plot(xATRTrailingStop, color=xcolor, title = "Trailing Stop")

plotshape(buySignal, title='Long Signal', text='Long', style=shape.labelup, location=location.belowbar, color=color.new(color.green, 0), textcolor=color.new(color.white, 0), size=size.small, offset = -1)
plotshape(sellSignal, title='Short Signal', text='Short', style=shape.labeldown, location=location.abovebar, color=color.new(color.red, 0), textcolor=color.new(color.white, 0), size=size.small, offset = -1)

I have already managed to get an exit signal that is not in the direction I want to appear, but exit signals that are in the same direction keep appearing repeatedly, and I would like it to appear only after the sell or buy signal, and nothing else.